The present invention relates to an instrument apparatus to be mounted, for example, on the vehicle, and more specifically, to a structure of illumination thereof.
As an instrument apparatus of this type, the one comprising an instrument body having a projecting drive shaft being mounted on the circuit board, a pointer that gleams with a light supplied from the center of the rotation thereof mounted on the tip of the drive shaft, and a front panel having a translucent display portion such as a scale or letters provided along the orbit of the pointer mounted behind the pointer, wherein the display portion of the front panel and the pointer are illuminated by the light source disposed behind the front panel is known.
More specifically, as shown in the publication of Japanese Patent Laid-Open No.105649/1997 for example, an instrument apparatus comprising an instrument body and a light source being disposed side-by-side in front of the circuit board, a light conductor of a shape bypassing the instrument body disposed behind the front panel, wherein a illuminating light is conducted to behind the front panel by the light conductor to illuminate the display portion (in this case, the pointer is also illuminated by the light conductor) is generally used. Such a structure that has a light conductor is advantageous in that the variations in illumination on the entire display portion can easily be prevented in comparison with the structure in which a plurality of light sources are disposed immediately under the front panel to illuminate the display portion directly (for example, see the publication of Japanese Utility Model Laid-Open No.33020/1993).
As shown in the publication of Japanese Patent Laid-Open No.21655/1997, for example, a structure in which an instrument body is disposed behind the circuit board, and a light source comprising a light emitting diode, a light conductor extending from the area in the vicinity of the drive shaft along the front panel toward the outside, and a reflector for supporting the light conductor from behind are disposed in the area in front of the circuit board (the area in the vicinity of the drive shaft) that is left as a free space because the instrument body is disposed behind thereof, so that the illumination is conducted to the outer periphery of the drive shaft by the light conductor to illuminate the display portion (in this case, the pointer is illuminated simultaneously by a direct light), is also known. Such a structure has many advantages such that the light source and the front panel can be disposed in the vicinity with each other by placing the instrument body behind the circuit board, that an uniform and blight illumination is realized while slimming the entire structure of illumination by providing a light conductor of a plate shape between the reflector and the front panel, and so on.
However, the instrument apparatuses shown in the publications of Japanese Patent Laid-open No.105649/1997 and Japanese Patent Laid-Open No.21655/1997 are both require the light conductor, and thus there is recognized problem in that the cost of parts and the weight of the entire apparatus increase and the structure of illumination in creases in complexity correspondingly. In addition, in the instrument apparatus shown in these publications, simply eliminating the light conductor may result in variations in illumination or lowering of luminance, thereby lowering the quality of the illumination significantly.
With these circumstanced in view, an object of the present invention is to provide an instrument apparatus in which at least a light conductive body can be eliminated for illumination of the front panel by improving the structure of illumination, so that weight reduction can be achieved at low cost.
The instrument apparatus of the present invention comprises: a circuit board; an instrument body disposed on the circuit board and provided with a drive shaft extending forward; a pointer to be fitted on the tip side of the drive shaft; a front panel disposed between the pointer and the circuit board and including a display portion having a scale, characters, and the like corresponding to the pointer; a light source disposed at the position in front of the circuit board and the inside (on the side where the drive shaft resides) with respect to the display portion, for illuminating the display portion; and a reflector to be disposed between the front panel and the circuit board. The reflector is formed with a first reflecting portion at the position facing to the light source in the direction of the axis of the drive shaft for reflecting a light from the light source toward the outer periphery, and with a second reflecting portion disposed outside (the position of the outer periphery) of the first reflecting portion extending outwardly with an airspace interposed between itself and the front panel so as to surround the light source for reflecting the illumination reflected from the first reflecting portion toward the front panel, so that the illumination conducted by the second reflecting portion illuminates the display portion.
In this manner, by illuminating the front panel (display portion) via the first and the second reflecting portion of the reflector, the front panel can be brightly and almost uniformly illuminated without using the light conductor. Therefore, a satisfactory quality of the illumination is achieved, and thus the light conductor can be eliminated for illuminating the front panel, thereby realizing cost reduction and weight reduction.
The light source is preferably disposed at a prescribed distance away from the display portion toward the side where the drive shaft resides, and the second reflecting portion is formed so as to cover the area behind the front panel including the display portion.
In the instrument apparatus of the present invention, illumination of the pointer may also be accomplished by disposing the instrument body behind the circuit board with the drive shaft passed through the circuit board, constructing the pointer of a light-emitting pointer that emits a light upon reception of the light supply from the center of rotation thereof, forming the front panel with a through hole for exposing the center of rotation of the pointer; disposing the light source at the position corresponding to the through hole, and forming the reflector with a opening at the position corresponding to the through hole for allowing the illumination to pass through and advance toward the center of rotation of the pointer.
In this case, since a light from the light source illuminates the display portion of the front panel via the first and the second reflecting portion of the reflector, and simultaneously, illuminates the pointer via the opening of the reflector and the through hole of the front panel, the light conductor can be eliminated not only for illuminating the front panel, but also for illuminating the pointer. In addition, since a common light source can be used for illuminate the front panel and the pointer, the necessity to specifically provide a light source for the pointer may be eliminated, thereby realizing cost reduction and weight reduction.
The light source may be disposed so as to face to the first reflecting portion in the direction of the axis of drive shaft, at the position where the illumination can be supplied toward the pointer through the opening of the reflector and the through hole of the front panel. By providing a cylindrical portion on the reflector within the first reflecting portion so as to surround the opening, the illumination from the light source can be guided toward the pointer, thereby increasing efficiency to illuminate the pointer.
The instrument apparatus of the present invention may also be constructed by disposing the instrument body behind the circuit board with the drive shaft passed through the circuit board, constructing the pointer of a light-emitting pointer that emits a light upon reception of the light supply from the center of the rotation thereof, forming the front panel with a through hole for exposing the center of rotation of the pointer, disposing a first light source for illuminating the pointer at the position corresponding to the through hole on the front side of the circuit board, disposing the second light source for illuminating the display portion at the position outside with respect to the first light source and on the side where the drive shaft resides (the inside) with respect to the display portion, providing the reflector with an opening for allowing the illumination from the first light source to pass through toward the center of rotation of the pointer, with a first reflecting portion facing to the second light source and reflecting the illumination from the second light source toward the outer periphery thereof, and with a second reflecting portion extending outwardly with an airspace interposed between itself and the front panel so as to surround the second light source for reflecting the illumination reflected from the first reflecting portion toward the front panel, so that the display portion and the pointer are simultaneously illuminated.
In this case, since the illumination from the first light source reaches the center of rotation of the pointer through the opening on the reflector and the through hole on the front panel to illuminate the pointer, and the illumination emitted from the second light source reaches the display portion of the front panel through the first and the second reflecting portion on the reflector to illuminate the display portion, the light conductor can be eliminated not only for illuminating the front panel, but also for illuminating the pointer, thereby realizing cost reduction and weight reduction. In addition, since the first and second light sources are provided for illuminating the front panel and the pointer respectively, the quantity of light reaching the front panel and the pointer may be increased, thereby increasing the illuminating luminance.
In this structure as well, the second light source is preferably disposed at a prescribed distance away from the display portion on the side where the drive shaft resides, and the second reflecting portion is formed so as to cover at least the area behind the front panel including a display portion.
When the first source for illuminating the pointer and the second light source for illuminating the front panel are provided as described above, by providing a partition surrounding the opening and extending in the direction of the axis of the drive shaft on the reflector so that the first light source and the second light source are separated by the partition, the partition can serve as a light guide portion for guiding the illumination from the first light source to the pointer to increase the illuminating efficiency of the pointer. When the reflector has a cylindrical portion surrounding the opening, the partition can be formed from the cylindrical portion continuously. In this case, it is also possible to provide the first reflecting portion on the partition. In such a structure, the structure of the reflector can be simplified.
In the structures described above, preferably, the first reflecting portion is inclined by a prescribed angle with respect to the front panel to form of an inclined surface or an inclined curved surface for reflecting a light from the light source toward the outer periphery (toward the second reflecting portion). In this case, by forming the inclined surface or the inclined curved surface constituting the first reflecting portion into a conical shape surrounding the drive shaft, a light from the light source can be reflected toward the outer periphery in good balance. The first reflecting portion can also be formed separately from the reflector.
In the structures described above, the second reflecting portion is preferably formed of an inclined surface or the inclined curved surface that approaches said front panel with the distance from the center. However, by providing the inclined surface or the inclined curved surface constituting the second reflecting portion so that the inclined angle with respect to the front panel increases with the distance from the center, the front panel can be illuminated more uniformly.
The instrument apparatus of the present invention comprises: a circuit board; an instrument body disposed on the circuit board and provided with a drive shaft extending forward; a pointer to be fitted on the tip side of the drive shaft; a front panel disposed between the pointer and the circuit board and including a display portion having a scale, characters, and the like corresponding to the pointer; a light source disposed at the position in front of the circuit board and the inside (the side where the drive shaft resides) with respect to the display portion, for illuminating the display portion, and a reflector to be disposed between the front panel and the circuit board. The light source is held by the circuit board in such a manner that the light-emitting portion faces toward the opposite side (outside) with respect to the side where the drive shaft resides, and the reflector is formed with a reflecting portion extending outwardly so as to surround the light source with an airspace interposed between itself and the front panel for reflecting the illumination emitted from the light-emitting portion toward the front panel, so that the illumination reflected on the reflecting portion reaches the front panel through the airspace to illuminate the display portion.
In this manner, the front panel can be illuminated brightly and almost uniformly without using the light conductor by reflecting the illumination from the light source of which the light-emitting portion faces toward the opposite side from the side where the drive shaft resides through the reflecting portion of the reflector. Therefore, a satisfactory quality of illumination can be realized, and thus the light concudtor can be eliminated for illuminating the front panel, thereby realizing cost reduction and weight reduction.
In the instrument apparatus of the present invention, but not limited to this structure, it is preferable to provide a plurality of light sources for illuminating the front panel (second light sources) on the concentric circles with the drive shaft as a center. With such an arrangement, bright and well-balanced illumination can be achieved.
The instrument apparatus of the present invention comprises: a circuit board; an instrument body disposed on the circuit board and provided with a drive shaft extending forward; a pointer to be fitted on the tip side of the drive shaft and emitting a light upon reception of the light supply from the center of rotation; a front panel disposed between the pointer and the circuit board and including a display portion corresponding to the pointer and a through hole for exposing the center of rotation of the pointer; a first light source disposed in front of the circuit board at the position corresponding to the through hole for illuminating the pointer; a second light source disposed outside with respect to the first light source in front of the circuit board but on the side where the drive shaft resides with respect to the display portion for illuminating the display portion; and a reflector disposed between the front panel and the circuit board. The first light source for illuminating the pointer is held on the circuit board in such a manner that the light-emitting portion faces toward the pointer (the front), and the second light source for illuminating the front panel is held by the circuit board in such a manner that the light-emitting portion faces toward the side where the drive shaft resides (the outside). On the other hand, the reflector is formed with an opening at the position corresponding to the through hole for allowing the illumination from the first light source for illuminating the pointer to pass through toward the center of rotation of the pointer and with a reflecting portion extending outward with an airspace interposed between itself and the front panel so as to surround the second light source for illuminating the front panel for reflecting the illuminating light from the second light source toward said front panel.
In such a manner, by illuminating the pointer by allowing the illumination from the first light source of which the light-emitting portion faces toward the pointer reach the center of rotation of the pointer through the opening on the reflector and the through hole of the front panel, and by illuminating the front panel by allowing the illumination from the second light source of which the light-emitting portion faces opposite from the side where the drive shaft resides to reach the front panel after reflecting on the reflecting portion of the reflector, the light conductor can be eliminated not only for illuminating the front panel, but also for illuminating the pointer, thereby realizing cost reduction and weight reduction. In addition, specifically providing the first and the second light sources for the front panel and the pointer respectively enables to increase the quantity of light reaching the front panel and the pointer respectively, thereby increasing the illuminating luminance.
In this case, when the reflecting portion is formed of an inclined surface or the inclined curved surface that approaches the front panel with the distance from the center thereof, the illuminating efficiency can be increased. In such a case, providing the inclined surface or the inclined curved surface constituting the reflecting portion so that the inclined angle with respect to the front panel increases with the distance from the center is advantageous to obtain a uniform illumination on the front panel.
When a partition surrounding the opening and extending in the direction of the axis of the drive shaft is provided on the reflector so that the first light source and the second light source are separated by the partition, the partition can serve as a light guide portion for guiding the illumination from the first light source to the pointer to increase the illuminating efficiency of the pointer.
In the instrument apparatus of the present invention, but not limited to this structure, when the first light source for illuminating the pointer and the second light source for illuminating the front panel are provided, it is preferable to provide a plurality of first and second light sources on the concentric circles with the drive shaft as a center. With such an arrangement, bright and well-balanced illumination can be achieved.
When the color of emitted light is different between the first light source and the second light source, employment of the partition for separating the first light source and the second light source is effective, because the partition can prevent interference of the colors of emitted lights from the respective light sources.
In the instrument apparatus of the present invention, when the first reflecting portion and the second reflecting portion are provided on the reflector, a reflecting film for enhancing the reflectivity of light may be provided on any one of the area of the front panel facing to the first reflecting portion or the same facing to the second reflecting portion. When providing only a reflecting portion on the reflector, a reflecting film for enhancing the reflectivity of light may be provided on the area of the front panel facing to the reflecting portion.
Since the reflecting film is provided in this way, the illumination supplied to the front panel may be increased to increase the illuminating luminance, thereby enabling the uniform and bright illumination.
When forming a reflecting film on the front panel, the illuminating efficiency can be increased by forming the reflecting film so as to avoid the area of display portion and to closely surround the display portion. Employing the reflecting film in a metallic color is advantageous to increase the efficiency of light reflection, and in this case, the efficiency of the light reflection can further be increased by forming the surface of the reflecting film in a mirror-finished surface. As a metallic color, a silver color has little effect on the color of the illumination and is good in general versatility. As a method of forming the reflecting film, for example, any suitable means such as vapor deposition, plating, painting and coating, printing, transcription, adhesion of light-reflex-processed film or a plate may be employed. However, in the case of providing a reflecting film on the front panel, formation by printing is most suitable.
In the instrument apparatus of the present invention, an arbitrary type of a movement for instrument may be employed as an instrument body. However, by arranging the instrument body behind the circuit board so that the drive shaft passes through the circuit board and extends forward, the body portion of the instrument body is not placed in front of the circuit board, and thus the flexibility of the layout of the light sources (first and second light sources) is enhanced. Such an arrangement of the instrument body is especially effective for the structure in which the light source is disposed behind the center of rotation of the pointer.
In the instrument apparatus of the present invention, the reflector may be formed of desired material such as a metal having a light reflecting property, a synthetic resin, and the like. However, forming the reflector of a synthetic resin of whitish color is effective for achieving the effective illumination or weight reduction, and in addition, the reflecting efficiency may be increased by forming the wall surface of the reflector into a glossy surface.
In the instrument apparatus of the present invention, though the light source, or the first and the second light sources may employ an arbitrary light emitting element, a light-emitting diode is preferable, in view of the directivity, the heat build-up, and the effect to the environment.
In the instrument apparatus of the present invention, since the front side of the front panel is covered with the semi-translucent panel of a dark color, at least the illuminated image on the front panel can be shown in high contrast against the dark background, and thus a quality appearance is added and marketability may be enhanced despite of it slow cost and light weight.